Recent events have placed the need for the development of reliable techniques for the rapid, low-level detection of NIAID Category A Priority Pathogens (Category A Pathogens) at an even more critical level. This project will develop deployable, nanoparticle-based, surface enhanced Raman scattering (SERS) diagnostic tests to fill this need. In so doing, this project will focus on serum markers for three well characterized Category A Pathogens (i.e., Bacillus anthracis, Clostridium botulinum toxin, and Yersinia pestis) in devising and performance-validating a multiplexed diagnostic panel based on the ultrasensitive detection of extrinsic Raman labels (ERLs) selectively bound to captured active pathogen antigens. ERLs will use unique Raman reporter molecules (RRMs) and monoclonal antibodies (mAbs) to selectively bind to captured antigens and to generate a markedly enhanced signal for ultra-low-level detection. Concurrently, we will also design and manufacture prototypes of a lightweight integrated, closed, sample-to-answer platform capable of reading the characteristic SERS spectrum from the ERLs when excited by a new diode laser. The platform will be field-deployable, have a desktop printer-size footprint, and have a readout of ~2 min for a 96-well microplate. As assays for the deactivated pathogens are validated in the laboratory the procedures will be transferred into a BSL-3 facility where methods for the active Category A Pathogen markers will be validated. When the prototypic Raman instruments and panel kits are available, they will be beta-tested and performance validated in the research laboratory (with deactivated markers) and in the BSL-3 facility (with active markers) at the U.S. Army's Dugway Proving Ground (DPG). This project represents a partnership between scientists and engineers at the University of Utah, B&W Tek, Inc. (a global leader in Raman spectroscopy and related automated instrumentation), and DPG.